SYNTHESES, CHARACTERIZATIONS AND TESTINGS OF CARBON NANOFIBRE FOR HYDROGEN ADSORPTION STUDIES

Abstract

Renewable energy (RE) has been declared as the fifth fuel
of Malaysia in addition to oil, gas, coal and hydropower.
One of REs which is hydrogen has become an alternative
fuel for transportation to replace petroleum. For sufficient
hydrogen storage, the system requires an inexpensive, safe,
low weight tank, comparable in to a gasoline tank with
capability of quick loading and unloading hydrogen fuel.
Carbon nanomaterials have been nominated as one of the
best medium to store hydrogen due to its light weight, low
cost production depending upon types of synthesis methods,
non-toxic and can be generated with improvement in its
storage capacity. The research work focuses on the
development of carbon nanofibers by using chemical vapor
deposition method. The development of catalysts such as
iron (III) oxide and nickel (II) oxide for the synthesis of
carbon nanofibers (CNFs) has also been investigated. The
capacity of the developed materials in hydrogen adsorption
is tested at 298K and the pressure is up to 100 bar using
gravimetric measurement technique. Sample imaging
observations using field emission electron microscopy
(FESEM) and transmission electron microscopy (TEM)
indicate that the synthesized CNFs have both platelet and
herringbone structure with little carbon nanotubes (CNTs).
Iron-based catalyst CNF (Fe-C) samples have diameter size
of 170 nm while nickel-based catalyst CNF (Ni-C) has
diameter size of 200 nm. Specific BET surface area of Fe-C
and Ni-C are 92.34 m²/g and 45.96 m²/g, respectively. Both
analysis which are energy-dispersive X-ray (EDX) and
thermogravimetric proved that purity of Fe-C is between
88% to 95% while purity of Ni-C is ranges from 95% to
97%. For iron-based catalyst CNF, the highest uptake is
0.46 wt % at 70 bar and for nickel-based catalyst CNF, the
highest uptake is 1.76 wt % at 70 bar.